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View Full Version : Dean Kamen's water filter
Syzygys 03-27-08, 08:24 AM This could be the next BIG thing in inventions, specially that clean water is going to be one of the big issues of the future. I saw this on the Colbert show, Kamen is the guy who invented the Segway among other things:
http://gizmodo.com/370698/first-vid-of-dean-kamens-miracle-water-distilleron-colbert
I wonder how much it costs....
Sciencelovah 03-27-08, 03:23 PM The distiller is a chemical-, membrane-, and filter-free water purifier (from that
link), said to be able to filter water from urine, oceans, poisons, etc.
Membrane filter, because of their pore size and/or certain material properties
are known to be able to remove just about anything, even virus, from water
(attached: membrane filtration range spectrum). I also wonder how much that
one costs, and more importantly, how much is the cost to operate, cleaning,
and replace it, because itīs what make today's membrane still so expensive...
http://www.geafiltration.com/images/technology/filtration_spectrum2.jpg
so how does this thing work?
now we need portable vapor vompression distiller machine
Currently, the machines costs about $100,000 but with mass production and better design they plan to cut it down to $1,000 to $2,000 per machine. ...
Sciencelovah 03-27-08, 03:46 PM so how does this thing work?
I don't know how about that one (lazy to play the video at this moment :p),
but from its description which claim can remove 50% of human disease, I
suspect it is either a Macrofiltration or an Ultrafiltration membrane (see the
spectrum image above and where does bacteria and virus fall in that range).
They (MF or UF) work based on the different of molecular size between the
membrane pore and the molecule that wants to be removed. Its just like
any other filter, only with very small pore size (see the microns size on the
bottom of the image).
Because of its very small hole /pore, it becomes very selective filter. On the
other hand, it is easily plugged or fouled, and requires a lot of energy to
pump the water through the membrane (as resistance is high).
If he said can filter ocean water, most probably he talks about the reverse
osmosis type. That one is called as 'non-porous' membrane. Besides this
types of membrane (which works based on molecular size or concentration
difference), there are also many other types of membrane. Maybe you can
google membrane filtration, and surely will find lots of links which better
describe it.
Positron 03-27-08, 03:52 PM keeping it clean seems to be the biggest issue. It looks very similar to reverse osmosis to me.
Sciencelovah 03-27-08, 03:57 PM keeping it clean seems to be the biggest issue. It looks very similar to reverse osmosis to me.
There are many 'engineering' method to slowing down the cleaning requirement,
such as applying backwash using air or using the filtered water itself by pumping
back the water or injecting air to the opposite direction of filtration periodically
during its operation, but such method also takes a lot of energy and hence costly.
Sciencelovah 03-27-08, 03:59 PM Currently, the machines costs about $100,000 but with mass production and better design they plan to cut it down to $1,000 to $2,000 per machine.
How much is the capacity per machine?
p.s: sorry for editing the format of your text, because I seems can't quote that one,
dunno why, so I just copy paste it
Michael 03-27-08, 06:07 PM I think most labs have a cheap water filter from Millipore. I'm not sure how often the filter needs changed? Maybe once a year at about $500-700/filter. The water is very pure.
Exhumed 03-27-08, 07:48 PM Not surprising for something on Colbert, there were little details. He said it was a vapor compression distiller. I googled them and did not find many details. He is not the only one selling it, I noticed.
Some site of someone selling such a distiller: http://www.aquatechnology.net/vaporcompressiondistillers.html
They have a very brief explanation. They basically seem to separate by boiling temperature and a few other things. I can't guess what "the baffling system" is supposed to be, or "the unique non-contacted liquid ring seal".
The boiling point difference could separate the water from some of the problematic small things that can't be filtered, like arsenic and other metals. Afterwards other methods mentioned could handle anything remaining? :shrug: idk.
It looks like something that would need maintenance. And given it's expense and probable operating costs it is not really a fit solution for the many people without clean water. I'm pretty sure lack of clean water in most places is -- for now -- a problem of expense, not availability. If so, an expensive filtering machine is not much of a improvement on the situation.
One of my professors is researching something that will be cheaper if it works. If it does I'll post about it :O
Syzygys 03-28-08, 09:18 AM Fraggle keeps refering to something called watercone. That is also some kind of water purification system and supposed to be cheap...
ElectricFetus 03-28-08, 09:59 AM There nothing special about this, unless they can prove it need less energy then any other system and is cheaper, personally I would just go with steam distillation... using solar thermal power.
Exhumed 03-28-08, 01:03 PM Sounds like a much more viable solution ElectricFetus.
Since you know about this stuff can you explain the basis of this method? :O
ElectricFetus 03-28-08, 01:30 PM I know nothing, the web knows all:
http://en.wikipedia.org/wiki/Vapor-compression_evaporation
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